Respiratory drug enters trial to halt Parkinson's disease

Ambroxol, a common mucolytic medicine used for respiratory diseases, is now undergoing clinical trials for treatment of Parkinson’s disease, according to investigators at the Van Andel Research Institute (VARI) in Grand Rapids, MI.

“With this trial, we’re moving beyond treating Parkinson’s symptoms. We want to actually slow or stop disease progression,” said Patrik Brundin, MD, PhD, Director of VARI’s Center for Neurodegenerative Science. “This drug—ambroxol—has performed exceptionally well in preclinical studies for Parkinson’s and is already approved to treat other conditions.”

Ambroxol has been used as an expectorant for years. More recently, studies have shown that ambroxol increases activity of the lysosomal enzyme glucocerebrosidase, which helps reduce the accumulation of the toxic protein alpha-synuclein—a defining aspect in all people with Parkinson’s. Moreover, mutations in the gene that encodes glucocerebrosidase are considered to be the greatest genetic risk factor for developing Parkinson’s.

“Our preclinical work suggests ambroxol may be an effective Parkinson’s treatment thanks to its ability to correct a dysfunctional protein that is prevalent in people carrying a genetic mutation associated with inherited Parkinson’s cases,” said the trial’s principal investigator Anthony Schapira, MD, DSc, Professor of Clinical Neurology at Institute of Neurology, University College London, in London, UK. “What is particularly interesting is the potential for ambroxol also to benefit Parkinson’s patients without these genetic mutations.”

This trial is a proof-of-concept, open-label study of 20 patients in the UK. The researchers will measure any changes in levels of alpha-synuclein in the cerebrospinal fluid of patients treated with ambroxol. If successful, it will shape a larger phase II study, the researchers predict.

“This new trial provides real hope that we are on the cusp of something truly life-altering—new therapies that show promise to improve the quality of life for the 7 to 10 million people worldwide who have Parkinson’s,” said Tom Isaacs, president and co-founder of The Cure Parkinson’s Trust, a research charity based in London, UK.

The ambroxol trial is being launched as part of the Linked Clinical Trials (LCT) initiative, a program spearheaded by The Cure Parkinson’s Trust in collaboration with the Van Andel Research Institute. LCT aims to significantly reduce the time and cost required to develop new therapies by focusing on existing, approved medications that have shown promise in preclinical laboratory studies for treating Parkinson’s.